KR20200089698A - Magnesium or aluminum metal member with black oxide film and method for manufacturing same - Google Patents

Abstract

A magnesium or aluminum metal member provided with a black oxide coating by anodization, having good hardness and excellent corrosion resistance, rather than a black coating film coated on a magnesium or aluminum metal substrate having a complicated shape, and a method for manufacturing the same to provide. The magnesium or aluminum metal member having a black oxide film is a magnesium or aluminum metal member on which an anodized film is formed on a magnesium or aluminum metal base made of magnesium or aluminum metal, and the anodized film includes magnesium hydroxide and magnesium oxide, respectively. In addition to aluminum hydroxide and aluminum oxide, vanadium and/or iron are included, and the anodized film has a black color with RGB of 18<R<154, 20<G<135, 20<B<118.

Description

Magnesium or aluminum metal member with black oxide film and method for manufacturing same

The present invention relates to a magnesium metal member or an aluminum metal member (hereinafter referred to as a magnesium or aluminum metal member) having a black oxide film, and a magnesium or aluminum metal member having a black color without coating in particular and a method for manufacturing the same It is about.

Here, the magnesium or aluminum metal is a concept including a magnesium metal or a magnesium alloy, an aluminum metal, and an aluminum alloy.

Magnesium, aluminum, magnesium alloys, and aluminum alloys are widely used in communication equipment and various parts because of their light weight and good workability.

On the other hand, since magnesium or aluminum is an active metal, it is corroded and cannot be used as it is. However, since coating adhesion is not good, chemical conversion treatment is performed as a coating undercoat treatment.

Particularly, in order to use magnesium or aluminum for optical use, it is desired to make it black so as not to reflect light, and for this reason, usually black coating is applied to magnesium or aluminum members.

Since such a black coating process is provided, the manufacturing process increases, leading to high cost.

In addition, the black coating film has a problem in corrosion resistance and the like, and also has a problem in adhesion.

Conventional magnesium or aluminum anodized films cannot grow any further in the thickness direction when they grow to a certain film thickness, and cannot grow any further in the thickness direction. In addition, in a complicated shape (low current portion), the film is thinner than other parts and becomes a non-uniform film.

For example, as a method for anodizing magnesium, for example, in Japanese Patent Publication No. 2002-515092 (Patent Document 1), magnesium or a magnesium alloy is immersed in an electrolyte as an anode, and a cathode is provided in the electrolyte. , Anodic oxidation method of magnesium or magnesium alloy comprising or consisting of passing an electric current in the electrolyte, the electrolyte having a pH above 7, and (1) ammonia or amine in water or a mixture of these two, and (2) A method of anodizing magnesium or magnesium alloys comprising or consisting of phosphoric acid or water-soluble phosphate is disclosed.

In addition, Japanese Patent Publication No. Hei 11-502567 (Patent Document 2), in a method for anodizing a magnesium-based material, prepares an electrolyte solution containing ammonia and prepares a cathode in the solution. Magnesium as the base, characterized in that it consists of preparing a material based on magnesium as an anode in the solution, and passing a current between the cathode and the anode through the solution to form a coating on the material It is a method of anodizing the material to be used, the ammonia is supplied in the solution of 1% to 33%w/v, and the solution contains a phosphate compound prepared in the range of 0.01 to 0.2 mol, the anode of magnesium An oxidation treatment method is described.

In addition, in Japanese Patent Publication No. 2004-538375 (Patent Document 3), as an anodizing method of a magnesium material, the magnesium material is anodized while being immersed in an aqueous electrolyte solution having a pH greater than 7 in the presence of phosphate. Disclosed is a method comprising a process, wherein the electrolyte solution further comprises a metal ion blocker.

However, the conventional anodized film formed on magnesium or aluminum metal has a metallic color, and in order to make it black to suppress reflection of light, after forming the anodized film, dyeing black, for example It is necessary to apply the coating, and thus the process becomes complicated, and the adhesion between the obtained black coating film and the anodized film becomes a problem.

Japanese Patent Publication No. 2002-515092 Japanese Patent Publication No. Hei 11-502567 Japanese Patent Publication No. 2004-538375

The present invention has been made in view of the above-mentioned conventional problems, and even in a complex-shaped magnesium or aluminum metal substrate, a uniform black anodized film is provided, has good hardness, and is excellent in corrosion resistance. An aluminum metal member and a method for manufacturing the same are provided.

The present invention has been found that, as a result of earnest research to achieve the above-mentioned problems, a specific component is included in the anodized film of the magnesium alloy member or the aluminum alloy member, thereby forming a thick, black anodized film.

The magnesium or aluminum metal member of the present invention is a magnesium or aluminum metal member in which an anodized film is formed on a magnesium or aluminum metal base made of magnesium or aluminum metal, and the anodized film includes magnesium hydroxide and magnesium oxide or aluminum hydroxide, respectively. In addition to aluminum oxide, vanadium and/or iron is included, and the anodized film has a black oxide film, characterized in that it has a black color of 18<R<154, 20<G<135, 20<B<118. It is a magnesium or aluminum metal member provided.

Suitably, the magnesium or aluminum metal member provided with the black oxide film is a magnesium or aluminum metal member provided with a black oxide film, characterized in that the anodized film further contains phosphorus.

More preferably, in the magnesium or aluminum metal member provided with any of the black oxide films, the film thickness of the anodized film is 1 to 100 μm, characterized in that the magnesium or aluminum metal member provided with a black oxide film to be.

More preferably, in the magnesium or aluminum metal member provided with any of the above black oxide films, the black oxide film is characterized in that the total amount (mass %) of vanadium and/or iron in the anodized film is 1 to 70%. It is a magnesium or aluminum metal member.

Method for producing a magnesium or aluminum metal member having a black oxide film of the present invention,

Magnesium or aluminum metal substrate as an anode, and electrolytic at a current density of 5 A/dm ² to 60 A/dm ² using an alkali or neutral solution of 20 to 70° C. containing iron and/or vanadium, and the corresponding magnesium Alternatively, an anodizing step of forming an anodized film containing vanadium and/or iron, in addition to magnesium hydroxide and magnesium oxide or aluminum hydroxide and aluminum oxide, each having a film thickness of 1 to 100 μm on an aluminum metal substrate,

A water washing step of washing the magnesium or aluminum metal member on which the anodized film is formed with water having a temperature of 5°C or higher and less than 60°C.

It is a manufacturing method of a magnesium or aluminum metal member provided with a black oxide film, characterized by comprising a.

Suitably, in the method for producing a magnesium or aluminum metal member having the black oxide film, the alkali solution or the neutral solution further comprises phosphorus, magnesium or aluminum metal having a black oxide film. It is a method of manufacturing a member.

Here, the magnesium metal substrate is a substrate made of a magnesium metal or a magnesium alloy, and means a member/part in a state before an anodized film is formed, and a magnesium metal member is a member/part in which an anodized film is formed on a magnesium metal substrate. It means. Further, the aluminum metal substrate is a substrate made of an aluminum metal or an aluminum alloy, and means a member/part in a state before an anodized film is formed, and an aluminum metal member means a member/part in which an anodized film is formed on an aluminum metal substrate. Is to do.

Since the magnesium or aluminum metal member provided with the black oxide film of the present invention can uniformly form a black anodized film on a magnesium or aluminum metal substrate having a complicated shape, it does not apply special coating and exhibits black color. It becomes possible to use a magnesium or aluminum metal member. Therefore, since it is not necessary to further form a coated film to make it black as in the prior art, the problem of adhesion of the black coated film is eliminated.

Further, the magnesium or aluminum metal member provided with the black oxide film of the present invention does not need to clean the surface of the magnesium or aluminum metal substrate forming the anodized film in advance, even if some impurities are attached and present. It is possible to provide a black anodized film as it is.

In this way, since a uniform black oxide film is formed on the magnesium or aluminum metal substrate having a complicated shape, reflection of light is suppressed, and it is possible to effectively use it for optical applications.

Further, the method of manufacturing a magnesium or aluminum metal member provided with the black oxide film of the present invention can form a black uniform oxide film even if it is a complicated shape. Therefore, it is not necessary to provide a coating process for black again after preparing the anodized film in order to form a black magnesium or aluminum metal member (part) as in the prior art, and the black oxide film of the present invention can be easily obtained. The provided magnesium or aluminum metal member can be manufactured.

In addition, it is possible to form the black oxide film of the thick film by using it as it is without needing to clean the surface of the magnesium or aluminum metal substrate forming the anodized film.

1 is a photograph of each magnesium metal member obtained by changing the current density in manufacturing a magnesium metal member having a black oxide film as an example of the present invention.
Fig. 2 is a photograph of each magnesium metal member obtained by changing the temperature of the anodizing solution in manufacturing a magnesium metal member having a black oxide film as an example of the present invention.
3 is a photograph of each magnesium metal member obtained by changing the time of anodization in manufacturing a magnesium metal member having a black oxide film as an example of the present invention.
4 is an electron micrograph of the anodized surface ((1) to (3)) and the magnesium metal base surface ((4) to (6)) of the magnesium metal member having a black oxide film as an example of the present invention. It is.
5 is a photographic view of a magnesium metal member obtained depending on a change in time when a magnesium metal member having a black oxide film as an example of the present invention is subjected to a corrosion test.
6 is a photograph of each aluminum metal member obtained by changing the current density in manufacturing an aluminum metal member having a black oxide film as an example of the present invention.
7 is a photograph of each aluminum metal member obtained by changing the temperature of the anodic oxidation solution in manufacturing an aluminum metal member having a black oxide film as an example of the present invention.
8 is a photograph of each aluminum metal member obtained by changing the time of anodization in manufacturing an aluminum metal member having a black oxide film as an example of the present invention.
Fig. 9 is an electron micrograph of the anodized surface ((1) to (3)) and the aluminum metal base surface ((4) to (6)) of the aluminum metal member provided with an exemplary black oxide film of the present invention. It is.
Fig. 10 is a photographic view of an aluminum metal member obtained depending on a change in time when an aluminum metal member having a black oxide film as an example of the present invention is subjected to a corrosion test.

Although this invention is demonstrated by the following form example, it is not limited to these.

The magnesium or aluminum metal member provided with the black oxide film of the present invention is a magnesium or aluminum metal member having an anodized film formed on a magnesium or aluminum metal substrate made of magnesium or aluminum metal, the anodized film comprising magnesium hydroxide and In addition to magnesium oxide or aluminum hydroxide and aluminum oxide, vanadium and/or iron are included, and the anodized film has a black color with RGB of 18<R<154, 20<G<135, 20<B<118. It is a magnesium or aluminum metal member provided with a black oxide film.

As a magnesium metal base material which can be used for the magnesium metal member provided with the black oxide film of the present invention, not only a magnesium metal base material made of pure magnesium, but also known magnesium alloys such as Mg, Zn, Al-based alloys, and Mg-Li-based alloys Any magnesium-based metal substrate, including, can also be applied, and the aluminum metal substrate that can be used for the aluminum metal member is not only an aluminum metal substrate made of pure aluminum, but also an Al·Mg·Mn-based alloy, Al·Cu Any aluminum-based metal substrate, including known aluminum alloys such as system alloys, can also be applied.

The magnesium or aluminum metal member of the present invention is formed by forming a black anodized film formed by anodizing on a magnesium or aluminum metal substrate.

The anodized film has a film thickness of preferably 1 to 100 μm, more preferably 5 to 50 μm, and a thin black film or a thick black film is formed. By being within the range of such a film thickness, a black anodized film having better hardness and more corrosion resistance can be provided on the magnesium or aluminum metal member, not on the black coated film.

When the film thickness is less than 1 µm, the anodized film of the magnesium or aluminum metal member is thin, resulting in insufficient hardness and corrosion resistance. On the other hand, when the thickness exceeds 100 µm, the processing time may be long, so productivity may be lowered. It may happen.

Here, in the present invention, the film thickness using a FIB (focused ion beam: Focused Ion Beam product number FB-2100; manufactured by Hitachi High Technologies), the analysis sample from a magnesium or aluminum metal member formed with a black oxide film Produced, and observed by using a TEM (Transmission Electron Microscope: Transmission Electron Microscope, product number JEM-2010FEF: manufactured by Nippon Denshi Co., Ltd.), to observe the surface and cross section of the magnesium or aluminum metal member, and to It represents the average value of the distance between the top of the formed anodized film and the boundary of the magnesium or aluminum metal substrate.

The magnesium or aluminum metal member provided with the black oxide film of the present invention can have a thick film thickness of the anodized film on the magnesium or aluminum metal member as described above. Conventionally, when the anodized film is formed up to a certain thickness, the film resistance increases, so that it is no longer formed in the thickness direction, and when the voltage is increased to increase the thickness, the film resistance is high. The anodized film does not generate cracks and may have a film thickness of 1 to 100 μm.

Further, even if the shape of the magnesium or aluminum metal member is complicated, cracks or the like do not occur and have a uniform film thickness.

The anodized film formed on the magnesium or aluminum metal substrate having the anodized film of the present invention includes vanadium and/or iron in addition to magnesium hydroxide and magnesium oxide or aluminum hydroxide and aluminum oxide.

When such vanadium and/or iron is included in the anodized film, it becomes possible to provide a black anodized film, and as conventionally, it is necessary to additionally provide a black coating film to the magnesium or aluminum metal member after the anodized film is provided. There is no.

As for the degree of blackness of the anodized film of the magnesium or aluminum metal member, the surfaces R, G, and B of the anodized film are, for example, using a color difference meter (model number NF 555, manufactured by Nippon Denshoku Kogyo Co., Ltd.). As measured, it is in the range of 18<R<154, 20<G<135, 20<B<118, preferably 50<R<75, 50<G<70, 50<B<65.

By providing a black film having such a range of R, G, and B, it becomes difficult to reflect light, for example, and it becomes possible to effectively use it for optical applications.

Preferably, the vanadium and/or iron of the anodized film is measured by an atomic component on the surface of the anodized film by EDS analysis (energy dispersive X-ray spectroscopy: model number JSM-5600, manufactured by Nippon Denshi Co., Ltd.). , For example, the sum of the content of vanadium and/or iron in the anodized film is 1 to 70% by mass, more preferably 15 to 40%, and the anodized film becomes black.

Moreover, among the anodized films containing vanadium and/or iron, magnesium hydroxide and magnesium oxide, or aluminum hydroxide and aluminum oxide are further included. More preferably phosphorus and the like are also included.

Corrosion resistance of the anodized film is further improved by including phosphorus in the anodized film, and the content of phosphorus in the anodized film is 10 to 30% by mass, preferably 10 to 20%. It is preferable in terms of improvement.

Moreover, it is preferable that the magnesium or aluminum metal member provided with the anodized film of the present invention has a surface shape of the anodized film, preferably an uneven shape, more preferably 5 to 100 nm.

When the unevenness of the surface is in the above-mentioned range, it is a dense film and corrosion resistance becomes better.

Moreover, by having the size uneven|corrugated shape of the said range, even if it becomes a thick film, a crack does not generate|occur|produce in a film, and a more robust film performance can be maintained.

In addition, the magnesium or aluminum metal member provided with the black anodized film of the present invention has a Vickers hardness of 300 to 600 on the surface of the anodized film, excellent abrasion resistance, and excellent corrosion resistance.

Next, a method of manufacturing the magnesium or aluminum metal member provided with the black anodized film of the present invention will be described with reference to specific examples.

A method of manufacturing a magnesium or aluminum metal member comprising the black anodized film of the present invention,

Magnesium or aluminum metal substrate as an anode, and electrolytic at a current density of 5 A/dm ² to 60 A/dm ² using an alkali or neutral solution of 20 to 70° C. containing iron and/or vanadium, and the corresponding magnesium Or in addition to magnesium hydroxide and magnesium oxide (in the anodized film on the magnesium metal substrate) or aluminum hydroxide and aluminum oxide (in the anodized film on the aluminum metal substrate), vanadium and / Or anodizing process to form anodized film containing iron,

A water washing step of washing the magnesium or aluminum metal member on which the anodized film is formed with water having a temperature of 5°C or higher and less than 60°C.

It is to be provided.

Since the black oxide film having hard hardness is obtained by the production method of the present invention, it is not necessary to separately provide a black coating step in order to obtain a black component.

Further, even if the shape of the magnesium or aluminum metal member is a complicated shape, cracks or the like do not occur and it is possible to provide a homogeneous film thickness.

The magnesium metal base material or the aluminum metal base material used in the production method of the present invention does not provide a process for specifically cleaning even when foreign substances such as organic substances are attached even if an oxide film is formed on its surface by contact with air. Instead, it can be applied to the production method of the present invention.

Incidentally, a removal step, a step of cleaning the surface of the magnesium or aluminum metal substrate, such as degreasing and washing, or a known surface activation step may be provided as necessary. Degreasing can be carried out, for example, by dipping a magnesium or aluminum metal substrate in an aqueous alkali solution such as sodium hydroxide.

In the anodic oxidation step, a known anodizing method is applied, in which a magnesium or aluminum metal substrate is used as an anode, an insoluble electrode is used as a cathode, and electrolysis is performed in an alkaline solution or a neutral solution containing vanadium and/or iron in the solution. can do. As the electrolytic method, for example, the surface of the magnesium or aluminum metal substrate is anodized by an electrolytic method such as a cyclic method, a constant current method, an electrostatic potential method, a pulse electrostatic method, and a pulse constant current method to include vanadium and/or iron. There is a method of forming an anodized film.

As the negative electrode, any material can be used as long as it does not react with an alkali solution or has a remarkably low conductivity. In general, an insoluble conductor plate such as platinum or stainless steel or carbon can be used.

In addition, the alkali solution or the neutral solution is not particularly limited, for example, sodium hydroxide, potassium hydroxide, and ammonium solutions can be exemplified, and one or two or more of them can be used in combination. Among these alkali solutions, potassium hydroxide is preferred from the viewpoint of the film appearance.

In addition, the alkali solution or the neutral solution is used at a temperature of 20 to 70°C, preferably 30 to 60°C, and by performing an anodizing process at the temperature, a dense anodized film having ultra-fine pores can be formed. have.

When the temperature is less than 20°C, the unevenness of the formed anodized film exceeds 100 nm, so that the corrosion resistance of the film is poor, and when the temperature exceeds 70°C, the anodized film becomes severely dissolved. It is not desirable because it cannot secure a certain thickness.

In the alkali solution or the neutral solution, vanadium and/or iron to be contained in the anodized film is blended. The anodized film of the present invention can be obtained by setting the blending amount of 0.03 to 0.2 mol/L of vanadium and 0.0002 to 0.005 mol/L of iron.

Vanadium contained in an alkali solution or a neutral solution is not particularly limited as long as it is dissolved in a solvent as an electrolyte salt, exhibits electrical conductivity, and has stability. For example, vanadium pentoxide, ammonium metavanadate, vanadium oxychloride, Sodium metavanadate, potassium vanadate, sodium vanadate, vanadium tetrachloride, vanadium oxysulfate, vanadium oxydichloride, vanadium oxide, vanadium trichloride, vanadium oxide, 13 vanadium oxide 13, and the like can be exemplified. Can be blended into an alkaline solution or a neutral solution to form an electrolytic solution.

In addition, iron contained in the alkali solution or the neutral solution is not particularly limited as long as it is dissolved in a solvent as an electrolyte salt, exhibits electrical conductivity, and has stability, for example, iron chloride, ammonium iron citrate, iron lactate, iron sulfate, Examples include iron gluconate, potassium hexacyanoferrate, sodium ethylenediamine tetraacetate, iron, and iron ammonium oxalate. These electrolyte salts can be blended in an alkaline solution or a neutral solution to form an electrolytic solution.

Moreover, it is preferable that phosphorus is contained in the said alkali solution or neutral solution.

Phosphorus contained in the alkali solution or the neutral solution may be exemplified by ammonium phosphate, ammonium hydrogen phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, and the like. It is also possible to mix the electrolyte salt in an alkali solution or a neutral solution. It is preferable that the compounding amount is 0.002 to 0.07 mol/L of phosphorus.

Further, if necessary, other electrolytes can be contained in the alkali solution or the neutral solution, and the electrolyte salt is not particularly limited as long as it is dissolved in a solvent, exhibits electrical conductivity, and has stability. For example, NaOH, Na ₂ CO ₃ , Na ₂ SO ₄ , K ₂ SO ₃ , Na ₂ SO ₃ , K ₂ SO ₃ , NaNO ₂ , KNO ₂ , NaNO ₃ , NaClO ₄ , CH ₃ COONa, Na ₂ B ₂ O ₇ , NaH ₂ PO ₂ , (NaPO ₃ ) ₆ , Na ₂ MoO ₄ , Na ₃ SiO ₃ , Na ₂ HPO ₃ and the like can be suitably used.

These concentrations are preferably in the range of 0.001 to 10 moles, more preferably 0.01 to 5 moles, from the viewpoint of effectively using vanadium or iron.

It is preferable that the two solvents of the electrolyte solution dissolve the electrolyte, for example, water, methanol, ethanol, carbitol, cellosolve, dimethylformamide, methylpyrrolidone, acrylonitrile, ethylene carbonite, isopropyl alcohol, acetone , Toluene, ethyl cellosolve, dimethyl formaldehyde, tetrahydrofuran, methyl ethyl ketone, benzene, ethyl acetate, and the like.

The temperature of the electrolytic solution cannot be uniquely specified since it is related to the solidification point or boiling point of the solvent, but is, for example, 20 to 70°C in an aqueous solution, preferably 30 to 60°C. By making the temperature of the electrolyte solution into such a range, it becomes possible to effectively form an anodized film.

In the anodizing step, the current density of electrolysis is 5 A/dm ² to 60 A/dm ² , preferably 5 A/dm ² to 20 A/dm ² , and the time is appropriately set to form a film thickness of 1 to 100 μm. To form an anodized film.

By setting the current density to 5 A/dm ² to 60 A/dm ² , a dense film having ultrafine pores with a film thickness of 1 to 100 μm can be formed.

Also the other hand, when the current density is less than 5A / dm ^2, the film formation speed is very slow does not thick film is obtained inferior in corrosion resistance of the coating film, 60A / exceed dm ² film formation rate is extremely faster with the film strength and not Adhesion falls.

Here, in the present invention, the current density indicates a value obtained by dividing the current value set by the power source (product number HKD-8200F; manufactured by Sansha Denki Seisakusho) by the surface area of the magnesium metal member.

For example, as an example, when vanadium and iron are used as an electrolytic solution using ammonium metavanadate and iron ammonium citrate in an aqueous solution of potassium hydroxide and diammonium hydrogen phosphate, potassium hydroxide is 1 to 30 g in the solution. /L, 1 to 30 g/L of ammonium hydrogen phosphate, 1 to 20 g/L of ammonium metavanadate, 1 to 20 g/L of ammonium citrate, and current density of 5 A/dm ² to 60 A/dm ² , Anodic electrolytic coating can be performed for 60 seconds to 15 minutes at a temperature of 20 to 70°C to form a black anodized film.

The anodized film formed in this way has R, G, and B in the above range, and has an uneven shape having fine pores.

Subsequently, the magnesium or aluminum metal member on which the black anodized film is formed is washed with water at a temperature of 5°C or more and less than 60°C, preferably 10 to 50°C.

By this water washing process, the alkali solution or the neutral solution adhered on the anodized film is removed.

When the temperature is less than 5°C, the alkali solution or the like attached to the anodized film is not sufficiently removed, and when the temperature is 60°C or more, sufficient strength is not obtained and the temperature falls.

By providing the manufacturing process of the present invention, even if the magnesium or aluminum metal substrate has a complicated shape, a film having a homogeneous thickness of 1 to 100 µm can be provided, and the film is subjected to anodization. R, G, and B of the coating can be made black in the range of R, G, and B, and it is difficult to reflect light, and particularly useful for optical components. In addition, it has high hardness and excellent corrosion resistance.

Example

The present invention is illustrated by the following examples, comparative examples and test examples.

However, in Examples and Comparative Examples, the following metal test plates, chemicals, and the like were used.

Magnesium metal substrate: AZ91D

Aluminum metal base: ADC12

Carbon plate material: manufactured by Toyo Carbon Co., Ltd.

Potassium hydroxide (KOH): Wako Pure Chemical Industries Ltd. (reagent)

Diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ): Wako Pure Chemical Industries Ltd. (Reagent)

Ammonium metavanadate (NH ₄ VO ₃ ): Wako Pure Chemical Industries, Ltd. (Reagent)

Iron ammonium citrate: manufactured by Wako Pure Chemical Industries, Ltd. (reagent)

Sodium tungstate (Na ₂ WO ₄ ): Wako Pure Chemical Industries Ltd. (Reagent)

(Example 1)

The magnesium metal substrate having the shape shown in Fig. 1 was immersed in an electrolytic solution having the component composition shown in Table 1 below, and subjected to constant current electrolysis using the anodic oxidation conditions shown in Table 2 to perform anodization.

Specifically, the magnesium metal substrate in the shape of FIG. 1 is not specifically pretreated, and the magnesium metal substrate is used as the anode, and the carbon plate material is used in an electrolytic solution heated to a temperature of about 50° C. with the component composition shown in Table 1. The anode was subjected to cathode electrolysis for 600 seconds under the conditions of (1) 5A/dm ² , (2) 10A/dm ² , (3) 15A/dm ² , (4) 20A/dm ² , using the cathode as the cathode. After forming the anodized film on the magnesium metal substrate, it was washed with water at 25°C and dried. The obtained magnesium metal members on which anodized films are formed are shown in Figs. 1(1) to (4). All were visually black. Incidentally, the white spot in the drawing is a spot painted with white magic after anodization in order to attach a sample number.

The average thicknesses of the obtained anodized films were (1) 4 µm, (2) 8.8 µm, (3) 15.8 µm, and (4) 36.8 µm (measured by a transmission electron microscope), respectively.

However, in the present invention, the current density represents a value obtained by dividing the current value set by the power source (product number HKD-8200F; manufactured by Sansha Denki Seisakusho) by the surface area of the magnesium metal member, and the film thickness is described above. As described above, an analytical sample was prepared from the obtained magnesium metal member using FIB (Focused Ion Beam product number FB-2100; manufactured by Hitachi High-Technologies), and TEM (transmission electron microscope: Transmission Electron Microscope product) No. JEM-2010FEF: manufactured by Nippon Denshi Co., Ltd. to observe the surface and cross section of the magnesium metal member, and measure the distance between the top of the anodized film formed on the surface of the magnesium metal member and the boundary between the magnesium metal substrate Indicates.

In addition, the atomic components of the anodized film surface of the magnesium metal member (1) to (4) of Example 1 and the surface of the magnesium metal substrate (AZ91D) were subjected to EDS analysis (energy dispersive X-ray spectroscopy: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 3 below.

From Table 3, the contents of vanadium and iron in the obtained anodized film were (1) 14.0%, (2) 22.8%, (3) 21.7%, and (4) 23.8% in total (mass%).

As a result of measuring R, G, and B of the surface of each obtained magnesium metal member, for example, in the case of (2) of Example 1, R was 64, G was 63, and B was 62. In the case of other examples, the measured values were all in the range of 18<R<154, 20<G<135, and 20<B<118.

Incidentally, the measurements of R, G, and B were measured using a color difference meter (model number NF 555, manufactured by Nippon Denshoku High School Co., Ltd.).

On the other hand, the magnesium metal substrate (AZ91D) itself had R of 460, G of 427, and B of 362, showing a silver color.

(Example 2)

In Example 1, 10A/dm ² , and the temperature of the anodized electrolyte was (1) 20°C, (2) 30°C, (3) 40°C, (4) 50°C, and (5) 60°C. It carried out similarly to Example 1 except having changed between. The obtained magnesium metal members are shown in Figs. 2(1) to (5). All were visually black.

The thickness of the obtained anodized film was measured in the same manner as in Example 1 above. The average of each film thickness was (1) 19.5 μm, (2) 18.2 μm, (3) 17.1 μm, (4) 14.2 μm, and (5) 9.5 μm (measured by a transmission electron microscope), respectively.

In addition, the atomic components of the surface of the anodized film of the magnesium metal member of (1) to (5) in Example 2 were the same as in Example 1, and EDS analysis (energy dispersive X-ray spectroscopy: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 4 below.

From Table 4, the content of vanadium and iron in the obtained anodized film is (1) 26.1%, (2) 24.2%, (3) 23.0%, (4) 24.8%, and (5) in total (mass%). It was 15.4%.

In addition, when R, G, and B of each obtained magnesium metal member were measured in the same manner as in Example 1, all were in the range of 18<R<154, 20<G<135, 20<B<118.

(Example 3)

The shape of the magnesium metal base material AZ91D is the shape of Fig. 3, the current density is 10 A/dm ² , and the anode electrolytic time is (1) 3 minutes, (2) 5 minutes, (3) 10 minutes, ( 4) It carried out similarly to Example 1 except having changed to 15 minutes. The obtained magnesium metal members are shown in Figs. 3(1) to (4). All were visually black.

The thickness of the obtained anodized film was measured in the same manner as in Example 1 above. The average of each film thickness was (1) 4 μm, (2) 5 μm, (3) 8.8 μm, and (4) 12 μm (measured by a transmission electron microscope), respectively.

In addition, the atomic component of the surface of the anodized film of the magnesium metal member (1) to (4) in Example 3 was the same as in Example 1, and EDS analysis (energy dispersive X-ray spectroscopy analysis: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 5 below.

From Table 5, the contents of vanadium and iron in the obtained anodized film were (1) 13.7%, (2) 17.1%, (3) 24.9%, and (4) 27.4% in total (mass%).

In addition, as a result of measuring the obtained R, G, and B of each magnesium metal member in the same manner as in Example 1, all of them were black in the range of 18<R<154, 20<G<135, 20<B<118. A magnesium metal member was obtained.

(Example 4)

The aluminum metal substrate having the shape shown in Fig. 6 was immersed in an electrolytic solution having the component composition shown in Table 1, and subjected to constant current electrolysis using the anodizing conditions shown in Table 2 to perform anodization.

Specifically, the aluminum metal substrate in the shape of FIG. 6 is not specifically pretreated, and the aluminum metal substrate is used as the anode, and the carbon plate material is used in the electrolytic solution heated to a temperature of about 50° C. with the component composition shown in Table 1. The anode was electrolyzed under the conditions of (1) 10A/dm ² , (2) 15A/dm ² , (3) 20A/dm ² , (4) 25A/dm ² , and the current density was 600 seconds, After forming the anodized film on the aluminum metal substrate, it was washed with water at 25°C and dried. The obtained aluminum metal members on which anodized films are formed are shown in Figs. 6(1) to (4). All were visually black.

The average thicknesses of the obtained anodized films were (1) 6.7 µm, (2) 15.6 µm, (3) 23.9 µm, and (4) 31.5 µm (measured by a transmission electron microscope), respectively.

However, in the present invention, the current density represents the value obtained by dividing the current value set by the power source (product number HKD-8200F; manufactured by Sansha Denki Seisakusho) by the surface area of the aluminum metal member, and the film thickness is described above. As described above, an analytical sample was prepared from the obtained magnesium metal member using FIB (Focused Ion Beam product number FB-2100; manufactured by Hitachi High-Technologies), and TEM (transmission electron microscope: Transmission Electron Microscope product) No. JEM-2010FEF: manufactured by Nippon Denshi Co., Ltd. to observe the surface and cross section of the aluminum metal member, and measure the distance between the top of the anodized film formed on the surface of the magnesium metal member and the boundary between the aluminum metal substrate Indicates.

Further, EDS analysis of the atomic components of the anodized surface of the aluminum metal member (1) to (4) of Example 4 and the surface of the aluminum metal substrate (ADC12) (energy dispersive X-ray spectroscopy: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 6 below.

From Table 6, the contents of vanadium and iron in the obtained anodized film were (1) 26.3%, (2) 31.0%, (3) 33.5%, and (4) 33.1% in total (mass%).

As a result of measuring R, G, and B of the surface of each obtained aluminum metal member, for example, in the case of (2) of Example 4, R was 67, G was 66, and B was 67. In the case of other examples, the measured values were all in the range of 18<R<154, 20<G<135, and 20<B<118.

Incidentally, the measurements of R, G, and B were measured using a color difference meter (model number NF 555, manufactured by Nippon Denshoku High School Co., Ltd.).

On the other hand, the aluminum metal substrate (ADC12) itself had R of 161, G of 162, and B of 163, showing a silver color.

(Example 5)

In Example 4, 15A/dm ² , and the temperature of the anodized electrolyte was (1) 20°C, (2) 30°C, (3) 40°C, (4) 50°C, and (5) 60°C. It carried out similarly to Example 4 except having changed between. The obtained aluminum metal members are shown in Figs. 7(1) to (5). All were visually black.

The thickness of the obtained anodized film was measured in the same manner as in Example 4. The average of each film thickness was (1) 31.8 μm, (2) 23.4 μm, (3) 21.7 μm, (4) 17.5 μm, and (5) 24.5 μm (measured by a transmission electron microscope), respectively.

Incidentally, the white spot in the drawing is a spot painted with white magic after anodization in order to attach a sample number.

Further, the atomic components of the surface of the anodized film of the magnesium metal member (1) to (5) in Example 5 were the same as in Example 4, and EDS analysis (energy dispersive X-ray spectroscopy: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 7 below.

From Table 7, the content of vanadium and iron in the obtained anodized film is (1) 31.3%, (2) 31.5%, (3) 29.9%, (4) 31.9%, (5) in total (mass%). It was 25.1%.

In addition, when R, G, and B of each obtained aluminum metal member were measured in the same manner as in Example 4, all were in the range of 18<R<154, 20<G<135, 20<B<118.

(Example 6)

The shape of the aluminum substrate (ADC12) is the shape of FIG. 8, the current density is 15A/dm ² , and the anode electrolytic times are (1) 3 minutes, (2) 5 minutes, (3) 10 minutes, and (4). ) It was carried out in the same manner as in Example 4, except that it was changed to 15 minutes. The obtained aluminum metal members are shown in Figs. 8(1) to (4). All were visually black.

The thickness of the obtained anodized film was measured in the same manner as in Example 4. The average of each film thickness was (1) 5.4 μm, (2) 11.8 μm, (3) 16.2 μm, and (4) 26.4 μm (measured by a transmission electron microscope), respectively.

In addition, the atomic component of the surface of the anodized film of the aluminum metal member of (1) to (4) in Example 6 was the same as in Example 4, and EDS analysis (energy dispersive X-ray spectroscopy: model number JSM- 5600, manufactured by Nippon Denshi Co., Ltd.). The results are shown in Table 8 below.

From Table 8, the contents of vanadium and iron in the obtained anodized film were (1) 19.2%, (2) 29.6%, (3) 31.9%, and (4) 33.9% in total (mass%).

In addition, when R, G, and B of each obtained aluminum metal member were measured in the same manner as in Example 4, all were in the range of 18<R<154, 20<G<135, 20<B<118.

(Test Example 1) State of the surface of the anodized film

The surface of the anodized film of the magnesium metal member of (2) 10A/dm ² in Example 1 was subjected to (1) 500 times, (2) using an electron microscope (model number JSM-5600, manufactured by Nippon Denshi Chemical Co., Ltd.). ) 1000 times, (3) 3000 times, the electron micrograph was taken. The photographs are shown in Figs. 4 (1) to (3).

For comparison, photographs taken at (4) 500 times, (5) 1000 times, and (6) 3000 times the surface of the magnesium metal substrate (AZ91D) itself are shown in FIGS. 4 (4) to (6).

From FIG. 4, it can be seen that rough surface irregularities are formed on the surface of the magnesium metal member of Example 1. Since the surface roughness of the magnesium metal member of the present invention increases, it becomes possible to increase the light absorption and to exhibit black color.

The surface of the anodized film of the aluminum metal member of (2) 15A/dm ² in Example 4 was subjected to (1) 500 times, (2) using an electron microscope (model number JSM-5600, manufactured by Nippon Denshi Chemical Co., Ltd.). ) 1000 times, (3) 3000 times, the electron micrograph was taken. The photographs are shown in Figs. 9(1) to (3).

For comparison, photographs taken at (4) 500 times, (5) 1000 times, and (6) 3000 times the surface of the aluminum metal substrate (ADC12) itself are shown in FIGS. 9 (4) to (6).

It can be seen from FIG. 9 that rough roughness is formed on the surface of the aluminum metal member of Example 4. Since the surface roughness of the aluminum metal member of the present invention increases, it becomes possible to increase light absorption and to exhibit black color.

(Test Example 2) Hardness

The Vickers hardness of the magnesium metal member (1) to (5) of Example 2 and the magnesium metal substrate (AZ91D) were measured as follows.

Specifically, the hardness was measured using an ultra-fine indentation hardness tester (Model: ENT-1100b, manufactured by Elionix).

Table 9 shows the results.

The Vickers hardness of the aluminum metal member (1) to (4) of Example 4 and the aluminum metal substrate (ADC12) were measured as follows.

Specifically, the hardness was measured using an ultra-fine indentation hardness tester (Model: ENT-1100b, manufactured by Elionix).

Table 10 shows the results.

From Tables 9 and 10, it can be seen that the hardness of the anodization of the magnesium or aluminum metal member of the present invention is hard.

(Test Example 3) Corrosion resistance

A magnesium metal member having an anodized film was obtained in the same manner as in Example 2 (2) using the magnesium metal substrate having the shape shown in FIG. 5.

Subsequently, this magnesium metal member was imposed on the salt spray test (JIS Z2371) to verify the condition after spraying the salt water continuously for the following (1) to (8) times. Specifically, (1) 24 hours later, (2) 48 hours later, (3) 72 hours later, (4) 96 hours later, (5) 12 hours later, (6) 144 hours later, (7) 168 hours later. Then, (8) the state after 192 hours is shown in Figs. 5(1) to (8).

It can be seen from FIGS. 5(1) to (8) that the obtained anodized films are excellent in corrosion resistance.

An aluminum metal member having an anodized film was obtained in the same manner as in Example 4 (2) using an aluminum metal substrate having the shape of FIG. 10.

Subsequently, this aluminum metal member was subjected to a salt spray test (JIS Z2371) to verify the state after spraying the salt water continuously for the following (1) to (8) times. Specifically, (1) 24 hours later, (2) 48 hours later, (3) 72 hours later, (4) 96 hours later, (5) 12 hours later, (6) 144 hours later, (7) 168 hours later. Then, the state after (8) 192 hours is shown in Figs. 10(1) to (8).

It can be seen from FIGS. 10(1) to (8) that the obtained anodized film has excellent corrosion resistance.

The magnesium or aluminum metal member of the present invention can be effectively used for optical applications because the anodized film is black and has high light absorption. In particular, it can be suitably used for exterior parts such as personal computer bodies, and has good hardness. , Because it has excellent chemical resistance, it can be applied to various mechanical, electrical, and electronic parts.

Claims (6)

A magnesium or aluminum metal member having an anodized film formed on a magnesium or aluminum metal base made of magnesium or aluminum metal, and the anodized film includes, in addition to magnesium hydroxide and magnesium oxide or aluminum hydroxide and aluminum oxide, vanadium and/or iron, respectively. It is a magnesium or aluminum metal member provided with a black oxide film, characterized in that the anodized film has a black color of 18<R<154, 20<G<135, 20<B<118. The magnesium or aluminum metal member according to claim 1, wherein the anodized film further contains phosphorus. The magnesium or aluminum metal member having a black oxide film according to claim 1 or 2, wherein the film thickness of the anodized film is 1 to 100 μm. The magnesium or aluminum having a black oxide film according to any one of claims 1 to 3, wherein the total amount (% by mass) of vanadium and/or iron in the anodized film is 1 to 70%. Metal member. Magnesium or aluminum metal substrate as an anode, and electrolytic at a current density of 5 A/dm ² to 60 A/dm ² using an alkali or neutral solution of 20 to 70° C. containing iron and/or vanadium, and the corresponding magnesium Alternatively, an anodizing step of forming an anodized film containing vanadium and/or iron, in addition to magnesium hydroxide and magnesium oxide or aluminum hydroxide and aluminum oxide, each having a film thickness of 1 to 100 μm on an aluminum metal substrate,
A water washing step of washing the magnesium or aluminum metal member on which the anodized film is formed with water having a temperature of 5°C or higher and less than 60°C.
A method of manufacturing a magnesium or aluminum metal member comprising a black oxide film, characterized in that it is provided. The method for producing a magnesium or aluminum metal member with a black oxide film according to claim 5, wherein the alkali solution or the neutral solution further comprises phosphorus.

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